/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.dtstack.taier.common.metric.stream.prometheus;

import com.dtstack.taier.common.exception.TaierDefineException;
import com.dtstack.taier.common.http.PoolHttpClient;
import com.dtstack.taier.common.metric.QueryInfo;
import com.dtstack.taier.common.metric.prometheus.HttpQueryRangeParamBuilder;


/**
 * 自定义 prometheus 查询器
 *
 * @author ：wangchuan
 * date：Created in 下午2:16 2021/4/16
 * company: www.dtstack.com
 */
public class CustomPrometheusMetricQuery<T> implements ICustomMetricQuery<T> {

    private final static String QUERY_RANGE_METHOD = "/api/v1/query_range?";

    private final static String HTTP_PREFIX = "http://";

    private final String queryRange;

    public CustomPrometheusMetricQuery(String prometheusAddr) {
        if (prometheusAddr.trim().startsWith(HTTP_PREFIX)) {
            this.queryRange = prometheusAddr.trim() + QUERY_RANGE_METHOD;
        } else {
            this.queryRange = HTTP_PREFIX + prometheusAddr.trim() + QUERY_RANGE_METHOD;
        }
    }

    @Override
    @SuppressWarnings("unchecked")
    public T queryRange(String metricName, Long startTime, Long endTime, QueryInfo queryInfo, Integer maxPoint) {
        String urlParam;
        try {
            urlParam = HttpQueryRangeParamBuilder.builder(metricName, startTime, endTime, queryInfo);
        } catch (Exception e) {
            throw new TaierDefineException("failed to build prometheus request param...", e);
        }
        String reqUrl = queryRange + urlParam;
        String result = PoolHttpClient.get(reqUrl, null);
        if (result == null) {
            return null;
        }
        return (T) CustomResultParser.parseResult(result, maxPoint);
    }
}
